1. Field of the Invention
The present invention relates in general to a stabilizer system installed on a vehicle for reducing or restraining rolling of a body of the vehicle, and more particularly to such a stabilizer system in which elastic force to be exerted by a stabilizer bar is changeable by an actuator having an electric motor.
2. Discussion of Related Art
In recent years, there has been developed a so-called “active stabilizer”, in detail, a stabilizer system in which elastic force to be exerted by a stabilizer bar is changed for effectively controlling or restraining rolling of a body of a vehicle. For instance, JP-A-2002-518245 and JP-A-2000-71738 disclose such a stabilizer system. The disclosed stabilizer systems include an electric motor whose operation is controlled for thereby effectively restraining the rolling of the vehicle body. In the disclosed stabilizer systems, the control of the operation of the motor is executed based on a rolling angle, a rolling moment, and so on, whereas the control of the operation of the motor is not executed in a range wherein the rolling is uncontrollable by the motor or the motor is overloaded.